Call centers have been used for decades to centralize the process of calling a number of related parties from a centralized physical location where a number of telephone agents work, or to handle incoming calls where a large volume of calls is expected. In order to assist call center agents, a number of technologies have been developed to assist in the operation and management of these call centers. This includes automated dialers that place outgoing calls using records retrieved from a database, as well as software to distribute information about each called party or incoming calling party for display at work stations where agents are located.
The growth in telemarketing and other applications for outbound call centers has created a need for more careful management of each call. For example, anyone who has received a call from a busy call center will recognize the tell tale “dead air” pause between their greeting (such as “hello”) and a response from an agent. During this time, the call center searches for an available agent to connect to the called party. There may also be difficulties for the called party when dial tone is not returned to the called party's telephone, which can prevent the called party from placing outbound calls for an extended time, even after the telephone has been hung up. In addition to creating a nuisance for called parties, these inefficiencies in conventional call centers can create cost and inconvenience for call centers and commercial providers within the Public Switched Telephone Network (“PSTN”).
While the Integrated Services Digital Network (“ISDN”) standard provides one established technique for connecting a call center to the PSTN, it has been widely ignored in call centers that make outbound calls. Generally, outbound call centers employ the cheaper and technologically simpler analog dialing alternatives, where digital signal processing is coupled with legacy local loop electronics to dial outbound calls and analyze in-band audio signals to detect the presence of a person at the receiving terminal. As a significant disadvantage, these local loop systems rely on in-band control signaling for operations such as dialing, on-hook detection, and off-hook detection. As a further disadvantage, they cannot independently control, for example, call tear down or the caller identification associated with an outbound call. These latter functions are under control of the PSTN core that interconnects central offices. While it is possible to send control messages to a central office concerning any of these telephone functions, it is not possible to do so using local loop, in-band signaling.
There remains a need for a system that brings the capabilities of out-of-band signaling to bear on managing the dead air and other inconveniences otherwise associated with analog-based call centers.